Magnetic resonance imaging (MRI) is an imaging method that is used primarily in medical diagnostics for representing the structure and function of the tissues and organs in the body. MRI is based physically on the principles of the nuclear spin resonance and is therefore also designated as nuclear spin tomography.
MRI may be used to generate slice images of the human (or animal) body that allow an assessment of the organs and of many pathological organ changes. Magnetic resonance imaging is based on strong magnetic fields and alternating electromagnetic fields in the radio-frequency range that resonantly excite specific atomic nuclei (e.g., the hydrogen nuclei/protons) in the body, which then induce electrical signals in the receiver circuit. No burdensome X-ray radiation or other ionizing radiation is generated or used in the device. Different relaxation times of different types of tissue are an essential basis for the image contrast. In addition, the different content of hydrogen atoms in different tissues (e.g., muscle, bone) also contributes to the image contrast.